The series finale could be an even bigger mismatch.
The Pirates will call up rookie Aaron Thompson to make his major league debut Wednesday afternoon against the Brewers and Shaun Marcum, who hasn't lost since the All-Star break and has twice dominated Pittsburgh this season.
Milwaukee (78-53) lost for the first time in 14 games to the Pirates in the nightcap of Monday's doubleheader, letting a seven-run seventh inning turn a 2-2 tie into a 9-2 Pittsburgh rout.
There was another seven-run inning at PNC Park on Tuesday, but this one belonged to the Brewers. Milwaukee pounded out seven of its 17 hits in the second inning, opening up a 7-0 lead en route to a 11-4 victory that, combined with St. Louis' loss, extended its NL Central lead to 10 games.
"(The Brewers are) playing very good baseball,'' Pirates manager Clint Hurdle said. "There is confidence everywhere with that club right now. They're confident swinging the bat and they have confidence when they're pitching.''
The bulk of Tuesday's damage came against Ross Ohlendorf, who was making just the third start of his injury-plagued season, but Wednesday's starter will be taking a major league mound for the first time.
With Kevin Correia and Paul Maholm on the disabled list, plus the need for another starter in Monday's doubleheader, the Pirates (60-68) were in a bit of a bind when it came to naming a starter for the series finale. They decided late Tuesday night to give that spot to Thompson, who has spent most of the season with Double-A Altoona.
The 22nd overall pick of the 2005 draft by the Marlins - one spot before Boston grabbed Jacoby Ellsbury - the left-hander has made three appearances since joining Triple-A Indianapolis, including two starts.
He pitched four innings in each of those, and didn't allow a run.
"I think regardless of results, I've been throwing the ball well," Thompson told the Pirates' official website. "Starting from spring training, I've really been working on getting back to what I did earlier in my career."
Even if Thompson can keep Pittsburgh in the game, his team's offense should have its hands full. Marcum (11-3, 3.40 ERA) is 4-0 since the All-Star break, and he's been especially good in his last two outings.
One of those came with 7 2-3 innings of one-run ball Aug. 14 against the Pirates - he has a 0.61 ERA in two starts versus Pittsburgh - and he was just as good Friday against the Mets. Marcum held New York to a run and six hits over seven innings in a 6-1 victory.
"I think at the beginning, I didn't see the velocity in his fastball, but he was still spotting it well," manager Ron Roenicke told the Brewers' official website. "Changeup was great, breaking ball was good, and then his velocity picked up. I thought he looked really good the last five or six innings."
Marcum's looked really good away from Miller Park all season. After losing his first road start in a Milwaukee uniform, he's 6-1 with a 2.25 ERA in his last 12 outings.